While household soft-ice-cream machines have been available to the public for many years, they have not gained wide acceptance. The known machines have a large number of moving parts making them both relatively expensive and difficult to keep clean. Since they are difficult to clean, they have not met standard hygenic requirements.
The known household soft-ice-cream machines operate with cooling cartridges in the form of a hollow cylinder. The manufacture of these cartridges is extremely expensive and substantially increases the price of the machines. Additionally, it is difficult to scrape the soft ice cream off these cylindrical cartridges. The primary parts of the machine, in particular the individual moving parts, are poorly accessible for cleaning. Additionally, several parts are accessible only when the machine is dismantled by an expert making it impossible for the home user to clean these parts.
Soft-ice-cream machines are known in which the gas pressure required is produced by the actuating of a hand pump. This embodiment has proven unsuitable, both from the standpoint of manufacture and with respect to cleaning and uniformity of the gas pressure upon the production of soft ice cream. It has furthermore been found that manual operation of the agitator mecessary for the production of soft ice cream is undesirable and that prior art household soft-ice-cream machines may deliver non-homogeneous soft ice cream as a result of irregularities which occur in the stirring process.